Exposure Analysis of Drinking and Dietary Contaminants in a Selected Population, Padaviya, Anuradhapura

Abstract

This study focused to analyse exposure of selected drinking and dietary contaminants and to assess the health risk for the selected population of Padaviya, Anuradhapura. Thirty families were randomly selected from which fifteen families were with the presence CKDu patients and other fifteen families were with absence of CKDu patients. Questionnaire based social survey was conducted and relevant data were collected for the risk analysis. Water, rice and soil samples were collected on family basis for the quality assessment. Nitrate-N, total hardness and fluoride varied within the range of 1.01 - 23.4 mg/L, 40.04 – 644.58 mg/L and 0.47 – 1.92mg/L respectively. All physiochemical parameters were significantly different among the wells (P<0.05). Water pH, conductivity and TDS in well water were below the Sri Lankan standard for portable water level (SLPWL). However, exceeded SLPWL value of NO3-N (C10, C14, C15& N3), hardness (C12 & C13) and fluoride (C7, C15 & N3) were observed in some wells. Both iron and copper concentrations in well water were lower than the provisional maximum tolerable daily intake (PMTDI) of WHO (Fe: 2 mg/L and Cu: 2 mg/L). Dietary iron and copper concentrations in rice were higher than the PMTDI of WHO (0.5 mg/kg) except for family N7. Copper and Iron varied within the range of 1.55 – 48.4 mg/kg dw and 467.08-893.61 mg/kg dw in soil respectively. Probable exposure concentration was higher than probable non-exposure concentration in the selected population. Therefore, Relative Risk for CKDu was greater than 1 for all selected contaminants and it explains that there is a possible risk due to drinking water and eating rice for the selected contaminants. Non-cancer risk values in selected families were higher than the unity of the risk level (1x10-6) and therefore the contaminants in drinking water and rice in Padaviya area can be considered as risk factors for prevailing chronic kidney disease.